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Diffstat (limited to 'doc/examples/muxing-example.c')
-rw-r--r-- | doc/examples/muxing-example.c | 542 |
1 files changed, 542 insertions, 0 deletions
diff --git a/doc/examples/muxing-example.c b/doc/examples/muxing-example.c new file mode 100644 index 0000000000..a1f19a47bf --- /dev/null +++ b/doc/examples/muxing-example.c @@ -0,0 +1,542 @@ +/* + * Copyright (c) 2003 Fabrice Bellard + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +/** + * @file + * Libavformat API example: Output a media file in any supported + * libavformat format. The default codecs are used. + */ + +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <math.h> + +#include "libavformat/avformat.h" +#include "libswscale/swscale.h" + +#undef exit + +/* 5 seconds stream duration */ +#define STREAM_DURATION 5.0 +#define STREAM_FRAME_RATE 25 /* 25 images/s */ +#define STREAM_NB_FRAMES ((int)(STREAM_DURATION * STREAM_FRAME_RATE)) +#define STREAM_PIX_FMT PIX_FMT_YUV420P /* default pix_fmt */ + +static int sws_flags = SWS_BICUBIC; + +/**************************************************************/ +/* audio output */ + +float t, tincr, tincr2; +int16_t *samples; +uint8_t *audio_outbuf; +int audio_outbuf_size; +int audio_input_frame_size; + +/* + * add an audio output stream + */ +static AVStream *add_audio_stream(AVFormatContext *oc, enum CodecID codec_id) +{ + AVCodecContext *c; + AVStream *st; + + st = av_new_stream(oc, 1); + if (!st) { + fprintf(stderr, "Could not alloc stream\n"); + exit(1); + } + + c = st->codec; + c->codec_id = codec_id; + c->codec_type = AVMEDIA_TYPE_AUDIO; + + /* put sample parameters */ + c->sample_fmt = AV_SAMPLE_FMT_S16; + c->bit_rate = 64000; + c->sample_rate = 44100; + c->channels = 2; + + // some formats want stream headers to be separate + if(oc->oformat->flags & AVFMT_GLOBALHEADER) + c->flags |= CODEC_FLAG_GLOBAL_HEADER; + + return st; +} + +static void open_audio(AVFormatContext *oc, AVStream *st) +{ + AVCodecContext *c; + AVCodec *codec; + + c = st->codec; + + /* find the audio encoder */ + codec = avcodec_find_encoder(c->codec_id); + if (!codec) { + fprintf(stderr, "codec not found\n"); + exit(1); + } + + /* open it */ + if (avcodec_open(c, codec) < 0) { + fprintf(stderr, "could not open codec\n"); + exit(1); + } + + /* init signal generator */ + t = 0; + tincr = 2 * M_PI * 110.0 / c->sample_rate; + /* increment frequency by 110 Hz per second */ + tincr2 = 2 * M_PI * 110.0 / c->sample_rate / c->sample_rate; + + audio_outbuf_size = 10000; + audio_outbuf = av_malloc(audio_outbuf_size); + + /* ugly hack for PCM codecs (will be removed ASAP with new PCM + support to compute the input frame size in samples */ + if (c->frame_size <= 1) { + audio_input_frame_size = audio_outbuf_size / c->channels; + switch(st->codec->codec_id) { + case CODEC_ID_PCM_S16LE: + case CODEC_ID_PCM_S16BE: + case CODEC_ID_PCM_U16LE: + case CODEC_ID_PCM_U16BE: + audio_input_frame_size >>= 1; + break; + default: + break; + } + } else { + audio_input_frame_size = c->frame_size; + } + samples = av_malloc(audio_input_frame_size * 2 * c->channels); +} + +/* prepare a 16 bit dummy audio frame of 'frame_size' samples and + 'nb_channels' channels */ +static void get_audio_frame(int16_t *samples, int frame_size, int nb_channels) +{ + int j, i, v; + int16_t *q; + + q = samples; + for(j=0;j<frame_size;j++) { + v = (int)(sin(t) * 10000); + for(i = 0; i < nb_channels; i++) + *q++ = v; + t += tincr; + tincr += tincr2; + } +} + +static void write_audio_frame(AVFormatContext *oc, AVStream *st) +{ + AVCodecContext *c; + AVPacket pkt; + av_init_packet(&pkt); + + c = st->codec; + + get_audio_frame(samples, audio_input_frame_size, c->channels); + + pkt.size= avcodec_encode_audio(c, audio_outbuf, audio_outbuf_size, samples); + + if (c->coded_frame && c->coded_frame->pts != AV_NOPTS_VALUE) + pkt.pts= av_rescale_q(c->coded_frame->pts, c->time_base, st->time_base); + pkt.flags |= AV_PKT_FLAG_KEY; + pkt.stream_index= st->index; + pkt.data= audio_outbuf; + + /* write the compressed frame in the media file */ + if (av_interleaved_write_frame(oc, &pkt) != 0) { + fprintf(stderr, "Error while writing audio frame\n"); + exit(1); + } +} + +static void close_audio(AVFormatContext *oc, AVStream *st) +{ + avcodec_close(st->codec); + + av_free(samples); + av_free(audio_outbuf); +} + +/**************************************************************/ +/* video output */ + +AVFrame *picture, *tmp_picture; +uint8_t *video_outbuf; +int frame_count, video_outbuf_size; + +/* add a video output stream */ +static AVStream *add_video_stream(AVFormatContext *oc, enum CodecID codec_id) +{ + AVCodecContext *c; + AVStream *st; + + st = av_new_stream(oc, 0); + if (!st) { + fprintf(stderr, "Could not alloc stream\n"); + exit(1); + } + + c = st->codec; + c->codec_id = codec_id; + c->codec_type = AVMEDIA_TYPE_VIDEO; + + /* put sample parameters */ + c->bit_rate = 400000; + /* resolution must be a multiple of two */ + c->width = 352; + c->height = 288; + /* time base: this is the fundamental unit of time (in seconds) in terms + of which frame timestamps are represented. for fixed-fps content, + timebase should be 1/framerate and timestamp increments should be + identically 1. */ + c->time_base.den = STREAM_FRAME_RATE; + c->time_base.num = 1; + c->gop_size = 12; /* emit one intra frame every twelve frames at most */ + c->pix_fmt = STREAM_PIX_FMT; + if (c->codec_id == CODEC_ID_MPEG2VIDEO) { + /* just for testing, we also add B frames */ + c->max_b_frames = 2; + } + if (c->codec_id == CODEC_ID_MPEG1VIDEO){ + /* Needed to avoid using macroblocks in which some coeffs overflow. + This does not happen with normal video, it just happens here as + the motion of the chroma plane does not match the luma plane. */ + c->mb_decision=2; + } + // some formats want stream headers to be separate + if(oc->oformat->flags & AVFMT_GLOBALHEADER) + c->flags |= CODEC_FLAG_GLOBAL_HEADER; + + return st; +} + +static AVFrame *alloc_picture(enum PixelFormat pix_fmt, int width, int height) +{ + AVFrame *picture; + uint8_t *picture_buf; + int size; + + picture = avcodec_alloc_frame(); + if (!picture) + return NULL; + size = avpicture_get_size(pix_fmt, width, height); + picture_buf = av_malloc(size); + if (!picture_buf) { + av_free(picture); + return NULL; + } + avpicture_fill((AVPicture *)picture, picture_buf, + pix_fmt, width, height); + return picture; +} + +static void open_video(AVFormatContext *oc, AVStream *st) +{ + AVCodec *codec; + AVCodecContext *c; + + c = st->codec; + + /* find the video encoder */ + codec = avcodec_find_encoder(c->codec_id); + if (!codec) { + fprintf(stderr, "codec not found\n"); + exit(1); + } + + /* open the codec */ + if (avcodec_open(c, codec) < 0) { + fprintf(stderr, "could not open codec\n"); + exit(1); + } + + video_outbuf = NULL; + if (!(oc->oformat->flags & AVFMT_RAWPICTURE)) { + /* allocate output buffer */ + /* XXX: API change will be done */ + /* buffers passed into lav* can be allocated any way you prefer, + as long as they're aligned enough for the architecture, and + they're freed appropriately (such as using av_free for buffers + allocated with av_malloc) */ + video_outbuf_size = 200000; + video_outbuf = av_malloc(video_outbuf_size); + } + + /* allocate the encoded raw picture */ + picture = alloc_picture(c->pix_fmt, c->width, c->height); + if (!picture) { + fprintf(stderr, "Could not allocate picture\n"); + exit(1); + } + + /* if the output format is not YUV420P, then a temporary YUV420P + picture is needed too. It is then converted to the required + output format */ + tmp_picture = NULL; + if (c->pix_fmt != PIX_FMT_YUV420P) { + tmp_picture = alloc_picture(PIX_FMT_YUV420P, c->width, c->height); + if (!tmp_picture) { + fprintf(stderr, "Could not allocate temporary picture\n"); + exit(1); + } + } +} + +/* prepare a dummy image */ +static void fill_yuv_image(AVFrame *pict, int frame_index, int width, int height) +{ + int x, y, i; + + i = frame_index; + + /* Y */ + for(y=0;y<height;y++) { + for(x=0;x<width;x++) { + pict->data[0][y * pict->linesize[0] + x] = x + y + i * 3; + } + } + + /* Cb and Cr */ + for(y=0;y<height/2;y++) { + for(x=0;x<width/2;x++) { + pict->data[1][y * pict->linesize[1] + x] = 128 + y + i * 2; + pict->data[2][y * pict->linesize[2] + x] = 64 + x + i * 5; + } + } +} + +static void write_video_frame(AVFormatContext *oc, AVStream *st) +{ + int out_size, ret; + AVCodecContext *c; + static struct SwsContext *img_convert_ctx; + + c = st->codec; + + if (frame_count >= STREAM_NB_FRAMES) { + /* no more frame to compress. The codec has a latency of a few + frames if using B frames, so we get the last frames by + passing the same picture again */ + } else { + if (c->pix_fmt != PIX_FMT_YUV420P) { + /* as we only generate a YUV420P picture, we must convert it + to the codec pixel format if needed */ + if (img_convert_ctx == NULL) { + img_convert_ctx = sws_getContext(c->width, c->height, + PIX_FMT_YUV420P, + c->width, c->height, + c->pix_fmt, + sws_flags, NULL, NULL, NULL); + if (img_convert_ctx == NULL) { + fprintf(stderr, "Cannot initialize the conversion context\n"); + exit(1); + } + } + fill_yuv_image(tmp_picture, frame_count, c->width, c->height); + sws_scale(img_convert_ctx, tmp_picture->data, tmp_picture->linesize, + 0, c->height, picture->data, picture->linesize); + } else { + fill_yuv_image(picture, frame_count, c->width, c->height); + } + } + + + if (oc->oformat->flags & AVFMT_RAWPICTURE) { + /* raw video case. The API will change slightly in the near + futur for that */ + AVPacket pkt; + av_init_packet(&pkt); + + pkt.flags |= AV_PKT_FLAG_KEY; + pkt.stream_index= st->index; + pkt.data= (uint8_t *)picture; + pkt.size= sizeof(AVPicture); + + ret = av_interleaved_write_frame(oc, &pkt); + } else { + /* encode the image */ + out_size = avcodec_encode_video(c, video_outbuf, video_outbuf_size, picture); + /* if zero size, it means the image was buffered */ + if (out_size > 0) { + AVPacket pkt; + av_init_packet(&pkt); + + if (c->coded_frame->pts != AV_NOPTS_VALUE) + pkt.pts= av_rescale_q(c->coded_frame->pts, c->time_base, st->time_base); + if(c->coded_frame->key_frame) + pkt.flags |= AV_PKT_FLAG_KEY; + pkt.stream_index= st->index; + pkt.data= video_outbuf; + pkt.size= out_size; + + /* write the compressed frame in the media file */ + ret = av_interleaved_write_frame(oc, &pkt); + } else { + ret = 0; + } + } + if (ret != 0) { + fprintf(stderr, "Error while writing video frame\n"); + exit(1); + } + frame_count++; +} + +static void close_video(AVFormatContext *oc, AVStream *st) +{ + avcodec_close(st->codec); + av_free(picture->data[0]); + av_free(picture); + if (tmp_picture) { + av_free(tmp_picture->data[0]); + av_free(tmp_picture); + } + av_free(video_outbuf); +} + +/**************************************************************/ +/* media file output */ + +int main(int argc, char **argv) +{ + const char *filename; + AVOutputFormat *fmt; + AVFormatContext *oc; + AVStream *audio_st, *video_st; + double audio_pts, video_pts; + int i; + + /* initialize libavcodec, and register all codecs and formats */ + av_register_all(); + + if (argc != 2) { + printf("usage: %s output_file\n" + "API example program to output a media file with libavformat.\n" + "The output format is automatically guessed according to the file extension.\n" + "Raw images can also be output by using '%%d' in the filename\n" + "\n", argv[0]); + exit(1); + } + + filename = argv[1]; + + /* allocate the output media context */ + avformat_alloc_output_context2(&oc, NULL, NULL, filename); + if (!oc) { + printf("Could not deduce output format from file extension: using MPEG.\n"); + avformat_alloc_output_context2(&oc, NULL, "mpeg", filename); + } + if (!oc) { + exit(1); + } + fmt= oc->oformat; + + /* add the audio and video streams using the default format codecs + and initialize the codecs */ + video_st = NULL; + audio_st = NULL; + if (fmt->video_codec != CODEC_ID_NONE) { + video_st = add_video_stream(oc, fmt->video_codec); + } + if (fmt->audio_codec != CODEC_ID_NONE) { + audio_st = add_audio_stream(oc, fmt->audio_codec); + } + + av_dump_format(oc, 0, filename, 1); + + /* now that all the parameters are set, we can open the audio and + video codecs and allocate the necessary encode buffers */ + if (video_st) + open_video(oc, video_st); + if (audio_st) + open_audio(oc, audio_st); + + /* open the output file, if needed */ + if (!(fmt->flags & AVFMT_NOFILE)) { + if (avio_open(&oc->pb, filename, AVIO_WRONLY) < 0) { + fprintf(stderr, "Could not open '%s'\n", filename); + exit(1); + } + } + + /* write the stream header, if any */ + av_write_header(oc); + + for(;;) { + /* compute current audio and video time */ + if (audio_st) + audio_pts = (double)audio_st->pts.val * audio_st->time_base.num / audio_st->time_base.den; + else + audio_pts = 0.0; + + if (video_st) + video_pts = (double)video_st->pts.val * video_st->time_base.num / video_st->time_base.den; + else + video_pts = 0.0; + + if ((!audio_st || audio_pts >= STREAM_DURATION) && + (!video_st || video_pts >= STREAM_DURATION)) + break; + + /* write interleaved audio and video frames */ + if (!video_st || (video_st && audio_st && audio_pts < video_pts)) { + write_audio_frame(oc, audio_st); + } else { + write_video_frame(oc, video_st); + } + } + + /* write the trailer, if any. the trailer must be written + * before you close the CodecContexts open when you wrote the + * header; otherwise write_trailer may try to use memory that + * was freed on av_codec_close() */ + av_write_trailer(oc); + + /* close each codec */ + if (video_st) + close_video(oc, video_st); + if (audio_st) + close_audio(oc, audio_st); + + /* free the streams */ + for(i = 0; i < oc->nb_streams; i++) { + av_freep(&oc->streams[i]->codec); + av_freep(&oc->streams[i]); + } + + if (!(fmt->flags & AVFMT_NOFILE)) { + /* close the output file */ + avio_close(oc->pb); + } + + /* free the stream */ + av_free(oc); + + return 0; +} |